1 files changed, 12 insertions, 7 deletions

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index f8c7ca3e8947..a930b72314ac 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1082,18 +1082,26 @@ static void rq_completed(struct mapped_device *md, int rw, bool run_queue)
         dm_put(md);
 }
 
-static void free_rq_clone(struct request *clone)
+static void free_rq_clone(struct request *clone, bool must_be_mapped)
 {
         struct dm_rq_target_io *tio = clone->end_io_data;
         struct mapped_device *md = tio->md;
 
+        WARN_ON_ONCE(must_be_mapped && !clone->q);
+
         blk_rq_unprep_clone(clone);
 
-        if (clone->q->mq_ops)
+        if (md->type == DM_TYPE_MQ_REQUEST_BASED)
+                /* stacked on blk-mq queue(s) */
                 tio->ti->type->release_clone_rq(clone);
         else if (!md->queue->mq_ops)
                 /* request_fn queue stacked on request_fn queue(s) */
                 free_clone_request(md, clone);
+        /*
+         * NOTE: for the blk-mq queue stacked on request_fn queue(s) case:
+         * no need to call free_clone_request() because we leverage blk-mq by
+         * allocating the clone at the end of the blk-mq pdu (see: clone_rq)
+         */
 
         if (!md->queue->mq_ops)
                 free_rq_tio(tio);
@@ -1124,7 +1132,7 @@ static void dm_end_request(struct request *clone, int error)
                         rq->sense_len = clone->sense_len;
         }
 
-        free_rq_clone(clone);
+        free_rq_clone(clone, true);
         if (!rq->q->mq_ops)
                 blk_end_request_all(rq, error);
         else
@@ -1143,7 +1151,7 @@ static void dm_unprep_request(struct request *rq)
         }
 
         if (clone)
-                free_rq_clone(clone);
+                free_rq_clone(clone, false);
 }
 
 /*
@@ -2662,9 +2670,6 @@ static int dm_init_request_based_queue(struct mapped_device *md)
 {
         struct request_queue *q = NULL;
 
-        if (md->queue->elevator)
-                return 0;
-
         /* Fully initialize the queue */
         q = blk_init_allocated_queue(md->queue, dm_request_fn, NULL);
         if (!q)